Ladies, here's another reason to defend that coffee habit you just can't kick. A new study found that java may protect against endometrial cancer, which begins in the lining of the uterus. It is the most common type of uterine cancer.

The research, published in the journal Cancer Epidemiology, Biomarkers & Prevention, examined data from the Nurses' Health Study, one of the largest and longest-running investigations of factors that influence women's health. Out of the more than 67,000 women enrolled in the study, researchers found that women who drank more than four cups of coffee per day were linked to a 25 percent reduced risk of endometrial cancer. Women who drank two to three cups per day reduced that risk by 7 percent.

"Women who regularly consumed coffee were at lower risk of endometrial cancer," said Dr. Edward Giovannucci. "Other studies had seen this association and because coffee lowers insulin levels and free estrogen levels, which are risk factors for endometrial cancer."

And it may not be the caffeine jolt that is the protective ingredient. Researchers found that those who drank two or more cups of day reduced the risk of the cancer by 22 percent.

"Endometrial cancer is associated with higher levels of estrogen and insulin," said Giovannucci. "Coffee appears to lower levels of estrogen and insulin in women. Coffee is also rich in antioxidants."

Several studies have found that coffee reduces the risk of several other medical conditions, including stroke, depression, dementia and several other cancers.

More than half of American adults drink some form of coffee each day, according to the National Coffee Association, and caffeine is the most frequently consumed stimulant in the world.

Despite the promising benefits, Giovannucci said it may be too early to recommend that women drink copious amounts of coffee.

"It may be premature to advise women to drink coffee to lower risk of disease," said Giovannucci. "It is also important to note that using substantial sugar or cream with coffee may offset some of the potential benefits. Also, too much caffeine may prove harmful to some people. Nonetheless, those who enjoy coffee should be reassured that the coffee itself does not seem to be harmful, and in fact, may even have some health benefits."

While the findings are promising, Marji McCullough, director of nutritional epidemiology at the American Cancer Society, said more study was needed.

"These results are intriguing, as the authors point out possible biological explanations," said McCullough. "However, additional large studies are needed to further explore associations with dose, and in subgroups.

"If a woman drinks coffee currently, this may be one benefit," said McCullough. "If not, there are other important ways to reduce the risk of endometrial cancer, such as maintaining a healthy body weight and staying physically active."